There are different classifications of birds, which are based on a variety of features. One of them is the degree of development of newborn chicks and the features of their further growth. According to this systematization criterion, two large groups are distinguished: brood birds, examples of which will be given in our article, and nesting birds. Let's take a closer look at them.
Nesting and brood birds: main differences
All representatives of this class reproduce by laying eggs, after incubating them. After a certain time, chicks hatch from the eggs. Brood birds are characterized by the fact that their newborn chicks are almost immediately ready for independent life. The body of the chicks is completely covered with down. It warms and protects the young body from adverse environmental conditions, and especially from sudden daily temperature changes. This allows such birds to immediately leave the nest and not freeze.
The eggs from which the brood birds hatch are quite large and containa large supply of valuable nutrients. The embryo uses them in order to achieve a significant degree of development while still in the shell and, almost immediately after hatching, to move on to independent life. Females have to incubate eggs for a long time - sometimes more than three weeks. Immediately after hatching, the chicks are able to see and hear well. Their muscular system is fully functional, which means they move independently. This is extremely important for protection against unexpected predators. After a few hours, the kids already know how to run fast and fly a little. And after a couple of weeks they can find food on their own.
Nesting birds hatch absolutely helpless chicks. They are born with bare skin, plumage, sight and hearing are absent. Sparrows, woodpeckers, cuckoos, pigeons, etc. are examples of nesting birds. After birth, they cannot stand on their feet, thermoregulation has not yet been formed. For these reasons, such chicks remain in the nest for a certain time, needing the care of their parents, who feed and warm them.
Semi-brood birds
There is also an intermediate group, whose representatives combine the features of both nesting and brood birds. For example, owl chicks are born blind and develop under the supervision of their parents, but are completely covered in plumage. But gulls stay in nests for a long time, despite the fact that they hatch both sighted and pubescent.
Habitat
Brood birds, whose representatives are quite diverse, are waterfowlor live on the ground. They do not build their nests high in trees. They are distinguished by their large body size and large mass. Therefore, chickens have the opportunity to slightly flit at first, gradually fully feathering. Waterfowl broods have weakly developed wings at first, devoting most of their time to developing swimming skills.
Now let's take a closer look at the main units of this group.
Cranes
The brood birds include all species of the crane-like order. They are characterized by a long neck and the same beak and legs. Due to the presence of loops in the trachea, they make characteristic sounds resembling a pipe. Being broods, crane-like birds build nests right on the ground. These are quite large birds, up to one and a half meters high. Their wingspan can reach two meters. The most common species of this order are gray, steppe and crowned cranes.
Anseriformes
Waterfowl brood birds (examples - swan, duck and mallard) belong to the order Anseriformes. Their characteristic feature is the presence of a wide and flattened beak. Inside its upper part are horny plates that serve to filter food particles from the water.
The saying "get out of the water" comes from anseriform birds. The thing is that they have a coccygeal gland, with the secret of which they lubricate their plumage. As a result, it becomes waterproof. Anseriformesserve as an important object of fishing, because they have tasty nutritious meat and fat, which has medicinal properties. It is worth mentioning warm feathers and down, which are used to fill blankets and pillows, as well as to obtain knitwear.
Thus, brood birds are more viable than nesting birds and are of great economic importance for humans.
